A material for producing an optical part such as an optical lens is required to exhibit high refractive properties and excellent transparency. Therefore, the refractive index of a resin (e.g., acrylic resin) that exhibits excellent transparency may be increased by adding inorganic particles, and the resulting resin may be used as a material for producing an optical part.
A method that prevents a decrease in transparency of a resin formed article by improving the dispersibility of inorganic particles in the resin formed article through a surface treatment of the inorganic particles has been studied.
For example, Patent Literature 1 discloses a transparent resin composite that includes specific metal oxide particles that have been surface-modified with an organic acid, and a transparent resin such as an acrylate resin.